1. Field of the Invention
This invention relates to an electronic card connector, and especially, is related to an electronic card connector which is connectable by inserting, in a single connector, electronic cards of different sizes.
2. Description of Related Art
As an electronic card connector which can insert, in a single connector, two electronic cards of different size, for example, the connector used for the Express Card is known.
The Express Card is specified by PCMCIA (Personal Computer Memory Card International Association/Portable Computer Memory Card International Association), and PCMCIA, as “Express Card Version 1.0”, in September, 2003, announced the two types of express cards, the “34 module” and the “54 module”, providing at the same time, recommended specifications of the connector so as to be able to connect each module to one connector. (For example, reference non-patent citation 1).
FIG. 5 is an exterior perspective view which shows the connection of the two kinds of module and the connector which are disclosed in the PCMCIA specification, and FIG. 6 is an exterior perspective view which turns upside down the connector of FIG. 5 and shows the connection with one of the modules.
The two kinds of Express Cards, that is, “34 module” (hereafter, module 1) and “54 module” (hereafter module 3), as shown in FIG. 5, are formed by a plate-shaped body of rectangular form which has, respectively, a long and short boundary, with specified length and prescribed thickness. Module 1 has opposing long boundaries 1a, 1b and short boundaries 1c, 1d, and a prescribed thickness, and connector 2 is installed on a portion of the short boundary 1d. In addition, elongated thin line protrusions 2a are formed at the end where the connector 2 is installed. This protrusion 2a, when the module 1 is inserted upside down, prevents connection to the later described connector's main body 11, and in addition, when module 1 is normally inserted, there is a mechanism which introduces the module 1 to the connector's main body 11 by contacting with the later described side rail 14.
Moreover, in the PCMCIA specification, the length L1 of the long boundary is 75 mm, and the length of the short boundary W1 is 34 mm, and the thickness is 5 mm.
Module 3 also has, in the same way, opposing long boundaries 3a and 3b and short boundaries 3c and 3d, and a prescribed thickness, and at the corner of the long boundary 3b and short boundary 3d, a notch 4 is formed by the respective shrinkage of prescribed length L4 within the long boundary 3b and W3 within the short boundary 3d. A connector 5 is installed on the short boundary 3d. 
Moreover, in the PCMCIA specification, the length L1 of the long boundary 3a is 75 mm, L4 is 22 mm, the length W2 of the short boundary is 54 mm, W3 is 20 mm, and the thickness is 5 mm.
The connector 10A to which each module 1, 3 is connected by insertion, as shown in FIG. 6, has a structure which provides the connector's main body 11 and a guide case 12 which is joined at one end of this connector's main body 11.
The guide case 12 is formed by a top plate 12a, by both side plates 12b, 12c which are formed by bending both side ends of this top plate, and by a back plate 12d which is formed by bending the side plate 12b further towards the side of the side plate 12c. This case 12 is formed by a bending process of a flat metal plate. In addition, the openings 13a, 13b of the narrow groove are formed between both side plates 12b, 12c. Within the openings 13a, 13b of each narrow groove, one of the openings 13a is formed to a size whereby the module 3 can be inserted. In addition, at the other opening 13b, the connector's main body 11 is installed.
Because the opening 13a is of a size which allows insertion of the large-scale module 3, it is possible to insert module 1 which has a smaller size than module 3, and because there results a common opening which allows insertion of both modules 1, 3, this opening can be referred to as a universal slot. Below, this universal slot is simply called “slot.”
In addition, the back plate 12d is inclined at one side of the side edges at a prescribed angle by directing from the slot 13a to the other opening 13b, and there is formed a guide surface, which guides towards the connector's main body 11, while in contact with the side end of the protrusion 2a of the module 1, forming the so-called side rail 14.
Each module 1, 3 is respectively connected by insertion to the connector 10A.
Because the opening of the slot 13a of the connector 10A is slightly larger than the exterior of the module 3, it is possible to smoothly insert module 3. That is, when inserting module 3 into slot 13a, the side surfaces 3a, 3b of the module are smoothly pushed in through guiding by the side plates 12b, 12c of the guide case, and the connector 5 of module 3 is connected with the connector's main body 11. In this contact state, because movement is controlled as the module 3 is bounded by the slot 13a and both side plates 12b, 12c, a stable connection is maintained.
However, when there is insertion of the small-sized module 1 in the slot 13a of connector 10A, because the size of the slot 13a has been made of a size that is appropriate for module 3, there results, between each side plate 12b, 12c which formed this slot 13a, for module 1, a so-called fitted state in which there is free movement play so that it is unknown whether there is good insertion at any site of the slot 13a. 
Because of this free movement, there is concern that there is not an appropriate connection between the connector 2 of module 1 and the connector's main body 11 within the case. In the PCMCIA specifications, as shown in FIG. 6, there is recommendation of the establishment of a side rail within the slot, making possible the avoidance of the above-mentioned drawback.